Templated self-assembly of nanoporous alumina : pore formation and ordering mechanisms, methodologies, and applications

Porous anodic aluminum oxide (AAO), also known as porous alumina, is a self-ordered nanostructured material well-suited for use in electronic, magnetic, optical and biological applications due to its small pore size (4-200nm) and spacing (10-500nm). Under slightly acidic conditions, both oxidation and dissolution of aluminum leads to the formation of pores. AAO pores form a self-assembled honey-comb structure with short range order over certain ranges of anodic potential and pH. In this work, three key results related to porous AAO science and technology are presented. First, a new theory based on strain-induced instability has been developed from the analysis of results obtained from kinetic studies and stress measurements to explain the formation of AAO pores. Experiments show that excess vacancies of aluminum, created by the dissolution process, generate a large tensile stress and an associated strain energy, which destabilizes the initially flat A1/AAO interface and leads to pore formation. Other factors affecting stability of the Al/AAO interface and the self-assembly process are also presented.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Krishnan, Ramkumar, 1975-

Advisor dc:contributor.advisor

• Carl V. Thompson.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/33610
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/33610

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33610